This invention relates generally to an improved installation tool for use with a liner sleeve attachment or attachment assembly, such as an adhesive bonded nutplate attachment assembly of the type described in U.S. Pat. No. 5,704,747, which is incorporated by reference herein. More particularly, the installation tool of the present invention is designed for expanding and/or flared deformation of a leading end of a liner sleeve seated with an opening formed in a substrate, for mechanically clamping and locking the liner sleeve onto the substrate, and for thereafter pulling a fixture pin from the attachment for substantially complete removal therefrom without interference.
U.S. Pat. No. 5,704,747 discloses an attachment or attachment assembly such as a nutplate assembly adapted for fixation onto the blind side of a selected substrate, such as onto a frame or panel used in an aerospace, marine or automotive application, wherein the attachment comprises or includes a liner sleeve for seated placement within an opening formed in the substrate. A fixture pin has an enlarged head engaged with the liner sleeve and an elongated mandrel projecting from the pin head and through the liner sleeve for access at a front side of the substrate. An installation tool is disclosed and includes pulling jaws for engaging and pulling the fixture pin mandrel. Initially, such pulling action displaces a tapered conical nose piece on the installation tool into deforming engagement with a leading end of the liner sleeve for flaring and locking the liner sleeve onto the substrate. Thereafter, continued pulling action causes the head on the fixture pin to collapse so that the fixture pin can be pulled forwardly and removed from the attachment. Such mechanical locking of the attachment onto the substrate by means of the liner sleeve may be supplemented by an adhesive bonding agent. In the case of a nutplate assembly, following fixture pin removal, a threaded nut is supported at the substrate blind side in substantial alignment with the substrate opening, for subsequent threaded engagement with a fastener such as a screw or bolt extending rearwardly through the substrate opening.
One disadvantage associated with blind side-mounted attachments and the related installation tool as described above is that the tapered nose piece on the installation tool can obstruct and interfere with complete and rapid pull-out separation of the fixture pin from the liner sleeve, following flared deformation of the liner sleeve leading end. That is, the tapered nose piece tends to remain seated against the flared liner sleeve to provide a stable support structure against which the pulling force may react to withdraw the fixture pin from the installed attachment. Accordingly, the fixture pin can be pulled forwardly until the collapsed head thereof engages the tapered nose piece seated on the liner sleeve, at which point the nose piece blocks further pull-out displacement of the fixture pin from the liner sleeve. At this point, the tool operator must manually pull the tool away from the substrate to achieve final fixture pin separation. Such step may require a significant exertion of manual effort, and, in some instances, may require the installation tool to be jockeyed or pivoted from side-to-side in order to extract the fixture pin head from the liner sleeve. Such side-to-side movements may undesirably cause surface damage to the installed liner sleeve.
A similar problem arises in connection with so-called cold working sleeve attachments of the type having a flanged rear or blind side end in combination with a tubular cold working liner sleeve projecting from the flanged rear end into a substrate opening. Such attachments are designed to receive a fixture pin having a relatively enlarged rear-end head engaging the flanged rear end of the sleeve, and an elongated narrow mandrel projecting forwardly from the head through the sleeve and substrate for access at a front side of the substrate. An installation tool includes pulling jaws for grasping and pulling the front side accessible mandrel so that the head urges the rear-end flange into firm seated engagement with the blind side of the substrate. Further pulling action carries the enlarged head of the fixture pin forwardly through the tubular liner sleeve for expanding the sleeve into secure engagement with the substrate. In some designs, this sleeve expansion action additionally cold-works the substrate in the region of the substrate opening for enhanced strength. However, as the enlarged head of the fixture pin is pulled through the attachment sleeve, a nose of the installation tool can interfere with complete and rapid pull-out separation of the head from the liner sleeve. For one example of a cold working sleeve attachment of this general type, see U.S. Pat. No. 4,732,518.
There exists, therefore, a need for improvements in and to installation tools of the type used for installing a liner sleeve attachment within a substrate opening, wherein the improved installation tool is designed for quick, easy, and sequential flared locking and/or expansion of a liner sleeve for secure engagement with the substrate followed by complete and positive fixture pin separation from the installed attachment. The present invention fulfills these needs and provides further related advantages.